I would like to prepare chloroplast DNA by using CsCl gradient.But I
still don't know how to prepare the CsCl gradient and how much CsCl
should I add in my chloroplast solution?Besides,how do I design the
centrifuge speed properly?The chloroplast DNA size is about
150Kb-170Kb.I will appriciate that anyone could tell me how to
prepare.

Duncan Clark <junk@[127.0.0.1]> wrote in news:nZViw+F+4Sl$EA5T@[127.0.0.1]:

Instead of Ethidium you might want to use bisbenzimide (Hoescht 33258 (I
think)). This causes separation based somewhat on AT content (primarily AT
runs). This might be needed to insure separation of the cpDNA from the
mtDNA that is probably present in your preparations.
Eric